A method for purifying quartz ore by reverse flotation based on an organic acid-inorganic salt system

Abstract

The application discloses a method for quartz ore reverse flotation purification based on an organic acid-inorganic salt system and belongs to the technical field of mineral processing flotation. The method comprises the following steps: performing grinding treatment on quartz ore containing quartz and aluminosilicate minerals to obtain a to-be-treated slurry; performing magnetic separation on the to-be-treated slurry to remove magnetic substances and obtain an intermediate ore slurry; performing quartz reverse flotation on the intermediate ore slurry in the presence of a quartz mixed depressant to obtain a quartz concentrate and aluminosilicate gangue minerals; the quartz mixed depressant is a mixture of an organic dicarboxylic acid and an inorganic salt, the inorganic salt is a phosphate and / or a silicate, and the mass ratio of the organic dicarboxylic acid to the inorganic salt is 2-3:1. The method realizes the reverse flotation of the quartz efficient depression through the green and pollution-free organic acid and the common inorganic salt, and is a method for preparing high-quality quartz from quartz ore and silicate tailings, which has high industrial application value and high feasibility.

Description

Technical Field

[0001] This invention relates to a method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system, belonging to the field of mineral processing flotation technology. Background Technology

[0002] Quartz, one of the most widely distributed and abundant rock-forming minerals in the Earth's crust, is not only a core component of pegmatite-type ores but also a highly promising associated resource in the tailings of numerous metal mines. High-quality quartz, with its excellent high-temperature resistance, corrosion resistance, and high insulation properties, has become an indispensable key material for strategic emerging industries such as photovoltaic glass, semiconductor chips, and fiber optic communications.

[0003] However, whether it is primary pegmatite or vein quartz, or secondary metal tailings, the quartz is often closely associated with aluminosilicate minerals such as feldspar. Since quartz and feldspar both belong to framework silicate minerals and are highly similar in physical and chemical properties, including magnetism, electrical properties, density, and crystal structure, achieving efficient separation of the two has always been a challenge in the field of mineral processing.

[0004] In current flotation purification processes, the separation of quartz and feldspar typically includes quartz direct flotation, represented by the "acid-free weak alkali method," and quartz reverse flotation, represented by the "fluorine-containing strong acid method." The acid-free weak alkali method for quartz direct flotation is highly sensitive to fluctuations in the composition of the raw ore, and the unavoidable mechanical entrainment during flotation results in poor quartz quality and low purity, making the obtained quartz product unsuitable for high-tech industries. Meanwhile, the traditional "fluorine-containing strong acid method" causes severe corrosion to equipment and significant environmental pollution, posing serious challenges to the working environment and the health of workers.

[0005] Chinese patent document (publication number CN119098291A) discloses a feldspar-quartz flotation combined collector and its application method. This feldspar-quartz flotation combined collector, by weight, comprises the following components: 1-2 parts dodecyltrimethylammonium chloride, 1.5-3 parts fatty acid salt, 1-2 parts nonionic surfactant, and 1 part inhibitor. Dodecyltrimethylammonium chloride exhibits good flotation collecting performance, while the active Al on the feldspar surface... 3+ It chelates with linoleate ions and adsorbs onto the feldspar surface. The sodium sulfate inhibitor in the flotation system reduces interfacial tension, increases the float-out rate of associated impurity minerals, and efficiently separates feldspar and quartz.

[0006] Chinese patent document (publication number CN121016943A) describes a method for graded crushing and grinding of granite pegmatite to obtain a slurry to be processed. The slurry is then subjected to wet magnetic separation to obtain a magnetically separated pulp and magnetic minerals. Without adjusting the pH of the pulp, reverse flotation is performed in the presence of a quartz mixed inhibitor to obtain feldspar and quartz products. The quartz mixed inhibitor is a combination of component A and component B. Component A is selected from at least one of sodium metasilicate, sodium tripolyphosphate, sodium hexametaphosphate, carboxymethyl cellulose, and brine glass. Component B is selected from at least one of guar gum, gum arabic, sodium humate, and citric acid. Although the quartz products prepared by this method have high purity, the recovery rate is low due to the relatively poor effect of the inhibitor. Furthermore, the actual industrial production process is difficult to control, and the process still needs improvement.

[0007] Therefore, breaking through the constraints of traditional technologies and developing a new reverse flotation purification process for quartz ore that is both green and ecological, highly efficient in separation, and has prospects for industrial application is of great practical significance for ensuring the security of strategic mineral resources of high-purity quartz and promoting the high-value utilization of solid waste resources. Summary of the Invention

[0008] To address the problems existing in the prior art, one of the objectives of this invention is to provide a method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system. This method is fluorine-free, environmentally friendly, and highly efficient in separating quartz ore from tailings containing quartz, making it feasible for industrial application. Furthermore, this method not only further increases the purity of quartz but also achieves a very high recovery rate.

[0009] To achieve the above objectives, a first aspect of the present invention provides a method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system, the method comprising:

[0010] (1) Grinding quartz ore containing quartz and aluminosilicate minerals to obtain a slurry to be processed;

[0011] (2) The slurry to be treated is subjected to magnetic separation to remove magnetic substances and obtain intermediate slurry;

[0012] (3) The intermediate slurry is mixed with quartz mixed inhibitor and collector for quartz reverse flotation to obtain quartz concentrate and aluminosilicate gangue minerals; the pH value of the quartz reverse flotation is 3.8~5;

[0013] The quartz mixed inhibitor is a mixture of organic dicarboxylic acid and inorganic salt, wherein the inorganic salt is phosphate and / or silicate, and the mass ratio of the organic dicarboxylic acid to the inorganic salt is 2~3:1;

[0014] The organic dicarboxylic acid is selected from at least one of maleic acid, tartaric acid, malic acid and oxalic acid;

[0015] The collector is a collector for aluminosilicate minerals.

[0016] This invention employs a combination of common, low-cost, and readily available organic dicarboxylic acids and inorganic salts as inhibitors. At a coarse particle size, this combination selectively inhibits quartz without harming the environment, ensuring efficient separation of quartz and gangue minerals (primarily feldspar) while significantly reducing grinding energy consumption. Through the combined action of the organic acid and inorganic salt, precise targeted synergistic adsorption on the quartz surface is achieved: the organic dicarboxylic acid regulates the pH throughout the process, maintaining the pulp pH at a weakly acidic level (pH 3.8-5) to prevent collectors from being excessively adsorbed onto the quartz surface via electrostatic interactions, thus preventing flotation degradation. Furthermore, as a crucial inhibitor component, it precisely matches and adsorbs onto the quartz surface through lattice matching with the inorganic salts, taking advantage of the different silanol / siloxy group spacings on the quartz and feldspar surfaces under acidic conditions. This increases the hydrophilicity of the quartz surface while simultaneously masking the collector's adsorption sites, inhibiting collector adsorption and significantly improving the separation efficiency of gangue minerals, primarily feldspar, and the quartz recovery rate.

[0017] In this invention, the aluminosilicate mineral is mainly feldspar.

[0018] As a preferred embodiment, the inorganic salt is selected from at least one of sodium phosphate, sodium pyrophosphate, sodium phosphate, and sodium silicate phosphate.

[0019] As a preferred embodiment, the mass ratio of the organic dicarboxylic acid to the inorganic salt is 2~2.5:1. Excessive organic dicarboxylic acid can lead to an excessively low slurry pH during quartz reverse flotation, resulting in decreased feldspar product quality and poorer separation efficiency. Excessive inorganic salt can cause inorganic salt enrichment in the return water, affecting slurry properties and thus inhibiting subsequent feldspar flotation. The mass ratio of the organic dicarboxylic acid to the inorganic salt is further preferably 2:1.

[0020] As a preferred embodiment, the quartz mixing inhibitor is a combination of tartaric acid and sodium pyrophosphate, a combination of malic acid and sodium phosphate, or a combination of maleic acid and sodium silicate. Experiments have shown that, under this preferred condition, the purity of silica in quartz concentrate can be further improved.

[0021] As a preferred embodiment, the silica content in the quartz ore containing quartz and aluminosilicate minerals is not less than 30%. More preferably, it is 60-90%.

[0022] As a preferred embodiment, the quartz ore containing quartz and aluminosilicate minerals is either quartz-bearing raw ore or quartz-bearing tailings; the quartz-bearing tailings are quartz-bearing tailings after molybdenum beneficiation and / or quartz-bearing tailings after tungsten beneficiation.

[0023] As a preferred embodiment, the quartz ore containing quartz and aluminosilicate minerals is quartz-bearing tailings. Experiments have shown that the method of the present invention still exhibits excellent flotation performance and high recovery rate for tailings with low quartz grades.

[0024] As a preferred embodiment, the particle size of the minerals in the slurry to be treated is -0.4 mm to +0.075 mm. More preferably, it is -0.25 mm to 0.1 mm.

[0025] As a preferred embodiment, the magnetic separation is a single-stage wet magnetic separation or a two-stage wet magnetic separation;

[0026] When using a single-stage wet magnetic separation, the magnetic field strength is 1.2T~1.5T. When using a two-stage wet magnetic separation, the magnetic field strength is 0.3T~0.5T in the first stage and 1.2T~1.5T in the second stage. When the mineral product contains a large number of strongly magnetic particles, if only a strong magnetic field of 1.2~1.5T is used for separation, some of the stronger magnetic particles will be adsorbed onto the magnetic separator, making it difficult to separate the remaining weaker magnetic particles from the slurry. Therefore, a two-stage magnetic separation is required.

[0027] As a preferred embodiment, the collector is a combination of anionic and cationic collectors;

[0028] The quartz reverse flotation adopts a process that combines roughing and scavenging.

[0029] As a preferred embodiment, the coarse selection is performed once or twice, and the sweep selection is performed 1 to 5 times.

[0030] As a preferred embodiment, the anionic collector is a fatty acid collector or a fatty acid soap collector.

[0031] As a preferred embodiment, the cationic collector is an amine collector.

[0032] As a preferred embodiment, the anionic collector is selected from at least one of sodium oleate, oxidized paraffin soap, and tal oil.

[0033] As a preferred embodiment, the amine collector is dodecylamine acetate and / or octadecylamine.

[0034] As a preferred option, during the roughing process, the amount of quartz mixed inhibitor added is 300~1500g / t, the amount of anionic collector added is 50~300g / t, and the amount of cationic collector added is 100~600g / t.

[0035] As a preferred option, during scavenging, the amount of quartz mixed inhibitor added is 50~1000g / t, the amount of anionic collector added is 25~300g / t, and the amount of cationic collector added is 50~500g / t.

[0036] As a more preferred method, during scavenging, the amount of quartz mixed inhibitor added is 50~1000g / t, the amount of anionic collector added is 25~250g / t, and the amount of cationic collector added is 100~500g / t.

[0037] It should be noted that the foam product obtained after roughing is the feldspar roughing product. Further refining of the feldspar roughing product involves using a higher concentration of quartz mixed inhibitor and a lower concentration of collector to further improve the flotation of quartz and low-quality feldspar, thus improving the overall quality of the feldspar. The flotation foam product is the feldspar concentrate product, while the residue at the bottom of the tank is the feldspar intermediate product.

[0038] As a preferred method, no frother is needed during the quartz reverse flotation process. Experiments have shown that adding a frother actually reduces the flotation recovery rate and the quartz suppression effect.

[0039] As a preferred option, when the flotation target is quartz-containing raw ore, it is first subjected to classification crushing before grinding. The classification crushing is a three-stage crushing process: first, the quartz ore is initially crushed to below 12 cm, then to 4-6 cm, and finally to below 3 cm.

[0040] When the flotation target is quartz tailings, only grinding is performed. During the grinding process, the crushed product is ground to -0.4mm to +0.075mm.

[0041] As a preferred embodiment, no additional pH adjuster is introduced during the quartz reverse flotation process. The organic dicarboxylic acid mixed inhibitor of this invention is acidic and can adjust the pH value. Furthermore, the mass ratio added in this invention results in high quartz separation efficiency, eliminating the need for additional pH adjusters. Without introducing additional pH adjusters, the pH value of the slurry in this invention is 3.8-5.

[0042] As a preferred embodiment, when mica is present in the quartz ore or tailings, flotation separation is performed to remove the mica before reverse flotation of the quartz. This invention does not impose any special requirements on the flotation method for separating mica; any method known in the art is acceptable.

[0043] Compared with the prior art, the present invention has at least the following advantages:

[0044] (1) Environmentally friendly and low equipment wear: The process of this invention is carried out in an organic dicarboxylic acid-inorganic salt slurry system without introducing any fluorine source. The weakly acidic environment also directly reduces equipment wear. At the same time, it eliminates the potential threat of toxic and harmful agents to the ecological environment and the health of operators, and has extremely high environmental benefits.

[0045] (2) High sorting efficiency and comprehensive resource utilization: By adopting a combined deep impurity removal process of "magnetic separation-flotation", this invention can efficiently and directionally separate iron-containing minerals and gangue such as mica from quartz and feldspar. This process not only significantly reduces the impurity content and significantly improves the purity of silica in quartz concentrate, but also simultaneously reduces the iron content in feldspar, realizing the high-value recovery of feldspar resources.

[0046] (3) Simplified process and high industrial adaptability: The entire process of this invention is clear and easy to operate and control. Under the premise of ensuring stable and reliable product quality, it greatly reduces the complexity of the process and provides technical support for large-scale continuous industrial production.

[0047] (4) High product quality: After purification by the process of this invention, the silica content of the quartz product obtained is stably 99.5% or higher. After purification, the silica content of the quartz tailings can reach 98.5% or higher, and the iron oxide content is strictly controlled within 0.02%. All indicators meet the stringent requirements of high-quality quartz raw materials. For ores with a high feldspar content (feldspar content greater than 40%), the produced by-product feldspar concentrate is of excellent quality, with an alumina content of more than 16.50% and an iron oxide content of less than 0.35%, which has extremely high commercial value. Attached Figure Description

[0048] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0049] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0050] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments. Obviously, the embodiments described below are only a part of the embodiments, and all other embodiments obtained by those skilled in the art without creative effort are still within the scope of protection of the present invention.

[0051] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0052] Example 1

[0053] In this embodiment, a granite pegmatite from Henan Province was selected as the raw ore. The content of its main substances was determined and is shown in Table 1.

[0054] The reverse flotation method provided in this embodiment specifically includes the following steps:

[0055] (1) Ore pretreatment: The ore is crushed to below 12cm using a jaw crusher; medium crushed to 4~6cm; and crushed to below 3cm using a double roll crusher. 500g of the crushed ore is weighed and ground using a ceramic ball mill. The particle size of the ore after grinding is controlled at -0.4mm~+0.1mm to obtain the slurry to be treated (slurry concentration is 30%).

[0056] (2) Magnetic separation: A vertical ring high gradient magnetic separator (magnetic induction intensity of 1.2T) is used to remove magnetic substances from the grinding product to obtain intermediate slurry;

[0057] (3) Quartz reverse flotation: A flotation process consisting of one roughing and one scavenging stage (no additional pH adjuster is introduced throughout the process; the pH of the pulp after adding flotation reagents is 3.8~4.5). During roughing, 800 g / t of quartz mixed depressant is added, along with 200 g / t of anionic collector and 400 g / t of cationic collector. The froth product obtained from roughing is high-quality feldspar. After roughing, the product in the flotation cell is scavenged. During scavenging, 400 g / t of quartz mixed depressant is added, along with 150 g / t of anionic collector and 250 g / t of cationic collector. The froth product obtained from scavenging is quartz intermediate product, and the product in the scavenging cell is quartz product.

[0058] In this embodiment, the anionic collector is sodium oleate; the cationic collector is dodecylamine acetate; and the quartz mixed inhibitor is composed of tartaric acid and sodium pyrophosphate in a mass ratio of 2:1.

[0059] Example 2

[0060] In this embodiment, a molybdenum tailings mine containing quartz and feldspar in Hebei Province was selected as the raw ore.

[0061] The reverse flotation method provided in this embodiment specifically includes the following steps:

[0062] (1) Crushing and grinding: The ore particles are mainly molybdenum tailings with a particle size of -20~+200 mesh, so only mineral grinding was carried out. 500g of mineral was weighed and ground using a ceramic ball mill, and then screened to obtain a product with a particle size of -60 mesh~+160 mesh to obtain the slurry to be processed (slurry concentration of 35%).

[0063] (2) Magnetic separation: Considering the properties of the ore, a slurry separator (magnetic induction intensity of 0.4T) and a high gradient magnetic separator (magnetic induction intensity of 1.2T) are used to perform magnetic separation on the product to remove magnetic substances and obtain magnetic concentrate and intermediate slurry;

[0064] (3) Mica and other impurity flotation: Due to the large number of impurities in the tailings, mica flotation is carried out to further remove components that interfere with the subsequent feldspar flotation. The mica flotation adopts a roughing and scavenging process. During the roughing process, 1800 g / t of mixed inhibitor is added, and the amount of anionic collector and cationic collector added is 100 g / t, without additional pH adjustment; during the scavenging process, 900 g / t of mixed inhibitor is added, the ratio remains unchanged, and the amount of anionic collector and cationic collector added is reduced to 50 g / t.

[0065] Quartz reverse flotation: A flotation process involving one roughing and two scavenging stages (no additional pH adjuster is introduced throughout the process; the pH of the pulp after adding flotation reagents is 4.0~4.2). During roughing, the dosage of mixed quartz depressant is 800 g / t, anionic collector is 300 g / t, and cationic collector is 600 g / t. For scavenging of the residue at the bottom of the tank, the dosage of mixed quartz depressant is 600 g / t, anionic collector is 250 g / t, and cationic collector is 500 g / t during the first scavenging stage; during the second scavenging stage, the dosage of mixed quartz depressant is 300 g / t, anionic collector is 100 g / t, and cationic collector is 200 g / t.

[0066] In this embodiment, the anionic collector is sodium oleate; the cationic collector is dodecylamine acetate; and the quartz mixed inhibitor is malic acid and sodium phosphate in a mass ratio of 2:1.

[0067] Example 3

[0068] In this embodiment, coastal sand from a certain area in Guangxi Zhuang Autonomous Region was selected as the raw ore.

[0069] This embodiment follows a similar method to Example 1, except that the raw ore is different. In this embodiment, the quartz mixed inhibitor is replaced with tartaric acid and sodium pyrophosphate at a mass ratio of 2.5:1. The amount of quartz mixed inhibitor used in each flotation process in this embodiment is the same as in Example 1. (No additional pH adjuster is introduced during the entire flotation process; the pH value of the pulp throughout the process after adding flotation reagents is 3.8~4.1).

[0070] Example 4

[0071] This embodiment is carried out using a method similar to that of Embodiment 1. The difference is that the quartz mixed inhibitor in this embodiment is replaced with maleic acid and sodium silicate in a mass ratio of 3:1, and the flotation reagent system and flotation process of quartz reverse flotation are adjusted. Specifically, one roughing and four scavenging are adopted. During roughing, 1500 g / t of mixed quartz inhibitor is added, along with 200 g / t of anionic collector and 350 g / t of cationic collector. During the first scavenging stage, 1000 g / t of mixed quartz inhibitor is added, along with 150 g / t of anionic collector and 250 g / t of cationic collector. During the second scavenging stage, 800 g / t of mixed quartz inhibitor is added, along with 100 g / t of anionic collector and 200 g / t of cationic collector. During the third scavenging stage, 500 g / t of mixed quartz inhibitor is added, along with 75 g / t of anionic collector and 150 g / t of cationic collector. (No additional pH adjuster is introduced during the entire flotation process; after adding flotation reagents, the pH value of the pulp throughout the process is 3.8~4.0.)

[0072] In this embodiment, the anionic collector is sodium oleate; the cationic collector is dodecylamine acetate; and the mixed inhibitor consists of maleic acid and sodium silicate in a mass ratio of 3:1. The preparation process of sodium silicate is as follows: metal sulfate and water glass are mixed in a molar ratio of 1:3, without introducing additional acid or alkali during the preparation process.

[0073] Example 5

[0074] This embodiment follows a similar method to Example 2 (using the same source of raw ore). In this embodiment, the quartz mixed inhibitor is replaced with malic acid and sodium phosphate at a mass ratio of 3:1. The amount of quartz mixed inhibitor used in each flotation process in this embodiment remains consistent with that in Example 1. (No additional pH adjuster is introduced during the entire flotation process; the pH value of the pulp throughout the process after adding flotation reagents is 3.6~3.8).

[0075] Example 6

[0076] This embodiment follows a similar method to Example 1 (using the same source of raw ore). In this embodiment, the quartz mixed inhibitor is replaced with oxalic acid and sodium silicate in a mass ratio of 3:1. The flotation process consists of one roughing and two scavenging stages.

[0077] During roughing, 1000 g / t of mixed quartz depressant is added, along with 220 g / t of anionic collector and 450 g / t of cationic collector. The froth product obtained from roughing is high-quality feldspar. After roughing, the product in the flotation cell undergoes secondary scavenging. In the first stage, 600 g / t of mixed quartz depressant, 100 g / t of anionic collector, and 200 g / t of cationic collector are added. In the second stage, 250 g / t of mixed quartz depressant, 75 g / t of anionic collector, and 180 g / t of cationic collector are added. The froth product from scavenging is intermediate quartz, and the product in the scavenging cell is quartz. No additional pH adjuster is introduced throughout the flotation process; the pH of the pulp throughout the entire process after adding flotation reagents is 4.0–4.3.

[0078] Example 7

[0079] This embodiment uses quartz pegmatite from a certain region in India, which has a relatively complex composition and contains many impurities. The specific composition is shown in Table 1. This embodiment performs two-stage magnetic separation and flotation. During flotation, oxalic acid and sodium silicate in a 3:1 ratio are used as a combined depressant. The flotation process consists of one roughing and three scavenging stages.

[0080] Step (1) is the same as in Example 1;

[0081] Step (2): Magnetic separation. Considering the properties of the ore, a vertical ring high gradient magnetic separator (magnetic induction intensity 1.2T) is used to perform magnetic separation on the product to remove weakly magnetic substances and obtain a slurry containing silicate minerals (mainly feldspar and quartz).

[0082] Step (3): During the roughing flotation of mica, 1200 g / t of quartz mixed inhibitor is added, and at the same time, 40 g / t of anionic collector and 80 g / t of cationic collector are added respectively to remove mica impurities.

[0083] Quartz reverse flotation: Following this, quartz reverse flotation roughing is performed, involving one roughing and three scavenging flotation processes. 300 g / t of mixed quartz depressant, along with 250 g / t of anionic collector and 500 g / t of cationic collector, are added. The resulting froth product is high-quality feldspar. After roughing, the remaining product in the scavenging tank is scavenged. The first scavenging stage adds 200 g / t of mixed quartz depressant, along with 150 g / t of anionic collector and 250 g / t of cationic collector. The second scavenging stage adds 150 g / t of mixed quartz depressant, along with 100 g / t of anionic collector and 200 g / t of cationic collector. The third scavenging stage adds 50 g / t of mixed quartz depressant, along with 50 g / t of anionic collector and 100 g / t of cationic collector. The scavenged froth product is intermediate quartz, and the tailings in the scavenging tank are high-quality quartz. No additional pH adjuster is introduced during the entire flotation process. After adding reagents, the pH value of the entire process is 4.3~4.6.

[0084] Comparative Example 1

[0085] The minerals are derived from the same source as in Example 1, wherein steps (1) and (2) are the same as in Example 1;

[0086] Quartz direct flotation: The pulp pH is adjusted to 10.5 using sodium hydroxide. A one-roughing, three-scavenging direct flotation process is employed. During roughing, 500 g / t starch, 200 g / t anionic collector, and 50 g / t metal ion activator are used as depressants. For the first scavenging, 100 g / t starch, 200 g / t anionic collector, and 40 g / t metal ion activator are used. For the second scavenging, 100 g / t starch, 100 g / t anionic collector, and 25 g / t metal ion activator are used. For the third scavenging, no depressants are used, only 50 g / t anionic collector and 10 g / t metal ion activator are added. The roughing product is quartz, and the final tailings in the flotation tank are feldspar.

[0087] The anionic collector was sodium oleate; the metal ion activator was calcium chloride; and the starch was corn soluble starch.

[0088] Comparative Example 2

[0089] This comparative example was conducted using a method similar to that of Example 1, with the mineral sourced from the same source as in Example 1. The difference was that sodium hydroxide was used to adjust the pulp pH to 6 during the quartz reverse flotation separation in this comparative example, while other parameters such as reagent types, dosages, and process parameters remained unchanged.

[0090] Comparative Example 3

[0091] This comparative example was conducted using the same procedure as Example 2, and the minerals were sourced from the same source as in Example 2. The difference was that the mixed quartz inhibitor in this comparative example was replaced with a single inhibitor (sodium phosphate), while keeping the total amount of inhibitor unchanged. (No additional pH adjuster was introduced during the entire flotation process; the pH of the pulp throughout the process was 6.5-7 after adding flotation reagents.)

[0092] Comparative Example 4

[0093] This comparative example was conducted using a method similar to that of Example 1 (using the same source of raw ore). The difference was that the quartz mixed inhibitor was replaced with tartaric acid and sodium pyrophosphate at a mass ratio of 8:1. The amount of quartz mixed inhibitor used in each flotation process in this example was consistent with that in Example 1. (No additional pH adjuster was introduced during the entire flotation process; the pH value of the pulp throughout the entire process was 2.5~2.8 after adding flotation reagents).

[0094] Comparative Example 5

[0095] This comparative example was conducted using a method similar to that of Example 2 (with the same source of raw ore). The difference was that the mixed quartz inhibitor was replaced with tartaric acid alone. The amount of quartz organic acid inhibitor used in each flotation process was the same as in Example 1. (No additional pH adjuster was introduced during the entire flotation process; the pH value of the pulp throughout the entire process after adding flotation reagents was 3.8~4.0).

[0096] Comparative Example 6

[0097] This comparative example was conducted using a method similar to that of Example 2 (using the same source of raw ore). The difference was that the quartz mixed inhibitor was replaced with a combination of citric acid and sodium phosphate at a mass ratio of 2:1. The amount of quartz mixed inhibitor used in each flotation process in this comparative example remained the same as in Example 2. (No additional pH adjuster was introduced during the entire flotation process; the pH value of the pulp throughout the entire process after adding flotation reagents was 4.6~4.8).

[0098] Comparative Example 7

[0099] This comparative example was conducted using a method similar to that of Example 2 (using the same source of raw ore). The difference was that the quartz mixed inhibitor was replaced with a combination of citric acid and sodium metasilicate at a mass ratio of 5:1. The amount of quartz mixed inhibitor used in each flotation process in this comparative example remained the same as in Example 2. (No additional pH adjuster was introduced during the entire flotation process; the pH value of the pulp throughout the entire process was 4.5~4.8 after adding flotation reagents).

[0100] Comparative Example 8

[0101] This comparative example was conducted using a method similar to Example 2 (with the same source of raw ore). The difference was that frother pine oil was added during the quartz reverse flotation process. The amount of frother added during roughing was 20 g / t, and no frother was added during scavenging.

[0102] Comparative Example 9

[0103] This comparative example was conducted using a method similar to that of Example 6, with the mineral sourced from the same source as in Example 1. The difference was that hydrochloric acid was used to adjust the pulp pH to 2.5 during the quartz reverse flotation separation in this comparative example, while other parameters such as reagent types, dosages, and process parameters remained unchanged.

[0104] Table 1

[0105]

[0106] As can be seen from Table 1, through Comparative Example 1, it is evident that positive flotation under alkaline conditions is difficult to guarantee the quality of quartz due to entrainment effects; while feldspar has a lower "sensitivity" to purity, and this method can yield high-quality feldspar and high-purity quartz.

[0107] Comparative Example 2 shows that after adjusting the pH value from weakly acidic to near neutral, a large number of quartz particles were found in the floating feldspar product. This indicates that a higher pH value leads to selective inhibition of quartz and significantly affects its separation from feldspar.

[0108] Comparative Example 3 shows that when only a single inorganic salt component is used as an inhibitor, fewer feldspar components float to the surface, resulting in a poor selective inhibition effect.

[0109] Comparative Examples 4 and 9 show that excessive use of organic dicarboxylic acids or hydrochloric acid, or excessively low pH values ​​in the flotation separation process, will reduce the purity of quartz.

[0110] Comparative Example 5 shows that when only a single organic dicarboxylic acid component is used as an inhibitor, fewer feldspar components float to the surface, resulting in a poor selective inhibition effect.

[0111] Comparative Examples 6 and 7 show that when using a combination of citric acid and sodium phosphate or a combination of citric acid and sodium metasilicate, the recovery rate of quartz decreases significantly, and the purity of the obtained quartz product also decreases.

[0112] As shown in Comparative Example 8, although the purity of quartz remains high after adding frother pine oil during the quartz reverse flotation process, its recovery rate is significantly improved.

[0113] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system, characterized in that: The method includes: (1) Grinding quartz ore containing quartz and aluminosilicate minerals to obtain a slurry to be processed; (2) The slurry to be treated is subjected to magnetic separation to remove magnetic substances and obtain intermediate slurry; (3) The intermediate slurry is mixed with quartz mixed inhibitor and collector for quartz reverse flotation to obtain quartz concentrate and aluminosilicate gangue minerals; the pH value of the quartz reverse flotation is 3.8~5; The quartz mixed inhibitor is a mixture of organic dicarboxylic acid and inorganic salt, wherein the inorganic salt is phosphate and / or silicate, and the mass ratio of the organic dicarboxylic acid to the inorganic salt is 2~3:1; The organic dicarboxylic acid is selected from at least one of maleic acid, tartaric acid, malic acid and oxalic acid; The collector is a collector for aluminosilicate minerals.

2. The method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 1, characterized in that: The inorganic salt is selected from at least one of sodium phosphate, sodium pyrophosphate, and sodium silicate phosphate.

3. A method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 1 or 2, characterized in that: The quartz ore containing quartz and aluminosilicate minerals is either quartz-containing raw ore or quartz-containing tailings; the quartz-containing tailings are quartz-containing tailings after molybdenum beneficiation and / or quartz-containing tailings after tungsten beneficiation. And / or, the particle size of the minerals in the slurry to be treated is -0.4 mm to +0.075 mm.

4. A method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 1 or 2, characterized in that: The magnetic separation is either a single-stage wet magnetic separation or a two-stage wet magnetic separation; When using a single-stage wet magnetic separation, the magnetic field strength is 1.2T~1.5T. When using a two-stage wet magnetic separation, the magnetic field strength of the first stage is 0.3T~0.5T and the magnetic field strength of the second stage is 1.2T~1.5T.

5. A method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 1 or 2, characterized in that: The collector is a combination of anionic and cationic collectors; The quartz reverse flotation adopts a process that combines roughing and scavenging.

6. The method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 5, characterized in that: The anionic collector is a fatty acid collector or a fatty acid soap collector. And / or, the cationic collector is an amine collector.

7. The method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 6, characterized in that: The anionic collector is selected from at least one of sodium oleate, oxidized paraffin soap and tal oil; And / or, the amine collector is dodecylamine acetate and / or octadecylamine.

8. A method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 5 or 6, characterized in that: During the roughing process, the amount of quartz mixed inhibitor added is 300~1500g / t, the amount of anionic collector added is 50~300g / t, and the amount of cationic collector added is 100~600g / t; And / or, during scavenging, the amount of quartz mixed inhibitor added is 50~1000g / t, the amount of anionic collector added is 25~300g / t, and the amount of cationic collector added is 50~500g / t.

9. A method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 5 or 6, characterized in that: When the flotation target is quartz-containing raw ore, it is first crushed into grades before grinding. The graded crushing is a three-stage crushing process: first, the quartz ore is crushed to less than 12 cm, then to 4-6 cm, and finally to less than 3 cm. When the flotation target is quartz tailings, only grinding is performed. During the grinding process, the crushed product is ground to -0.4mm to +0.075mm.

10. A method for reverse flotation purification of quartz ore based on an organic acid-inorganic salt system according to claim 1 or 2, characterized in that: No additional pH adjuster is introduced during the quartz reverse flotation process; And / or, the mass ratio of the organic dicarboxylic acid to the inorganic salt is 2~2.5:1; And / or, no frother is required during the quartz reverse flotation process.

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